Signing a message with HDWalletProvider?

Question

This works fine:

const provider = new Web3.providers.HttpProvider('http://localhost:8545');
const web3 = new Web3(provider);

await web3.eth.sign(message, address);

But when I switch to this provider:

const provider = new HDWalletProvider(mnemonic, "https://rinkeby.infura.io/<key>", 0 )

I get this error:

TypeError: self.signMessage is not a function

Anyone know what might be the issue?

Thanks!

edit I guess it's not implemented. Anyone know an alternative way to sign something using Infura?